This invention relates generally to semiconductor processing and, more particularly, to a gas delivery system for a chemical vapor deposition chamber suitable for high density plasma gapfill processing.
The fabrication of integrated circuits (ICs) involves performing a number of processes on the substrate, including the deposition of layers on the substrate and filling of gaps in the substrate. To achieve high throughput, it is important to minimize the particles or other contaminants so that more substrates can be processed between cleaning.
Chemical vapor deposition (CVD) is a gas reaction process used in the semiconductor industry to form thin layers or films of desired materials on a substrate. Some high density plasma (HDP) enhanced CVD processes use a reactive chemical gas along with physical ion generation through the use of an RF generated plasma to enhance the film deposition by attraction of the positively charged plasma ions onto a negatively biased substrate surface at angles near the vertical to the surface, or at preferred angles to the surface by directional biasing of the substrate surface.
The use of high RF power in HDP-CVD results in improved gapfill, particularly for gaps having a width of equal to or less than about 90 nm and an aspect ratio of at least about 4. For example, the source RF power is at least about 10 kW for processing 200 mm substrates and the source RF power is at least about 12 kW for processing 300 mm substrates. The use of high RF power, however, has been shown to cause an increase in particles, resulting in low throughput.